Management of multidrug-resistant tuberculosis and patients in retreatment

Analysis on time delay of tuberculosis among adolescents and young adults in Eastern China

Background

Tuberculosis (TB) is recognized as a significant global public health concern. Still, there remains a dearth of comprehensive evaluation regarding the specific indicators and their influencing factors of delay for adolescents and young adults.

Methods

All notified pulmonary TB (PTB) patients in Jiaxing City were collected between 2005 and 2022 from China's TB Information Management System. Logistic regression models were conducted to ascertain the factors that influenced patient and health system delays for PTB cases, respectively. Furthermore, the impact of the COVID-19 pandemic on local delays has been explored.

Results

From January 1, 2005 to December 31, 2022, a total of 5,282 PTB cases were notified in Jiaxing City, including 1,678 adolescents and 3,604 young adults. For patient delay, female (AOR: 1.18, 95%CI: 1.05-1.32), PTB complicated with extra-pulmonary TB (AOR: 1.70, 95% CI: 1.28-2.26), passive case finding (AOR: 1.46, 95% CI: 1.07-1.98) and retreatment (AOR: 1.52, 95% CI: 1.11-2.09) showed a higher risk of delay. For health system delay, minorities (AOR: 0.69, 95% CI: 0.53-0.90) and non-students (AOR: 0.83, 95% CI: 0.71-0.98) experienced a lower delay. Referral (AOR: 1.46, 95% CI: 1.29-1.65) had a higher health system delay compared with clinical consultation. Furthermore, county hospitals (AOR: 1.47, 95% CI: 1.32-1.65) and etiological positive results (AOR: 1.46, 95% CI: 1.30-1.63) were associated with comparatively high odds of patient delay. Contrarily, county hospitals (AOR: 0.88, 95% CI: 0.78-1.00) and etiological positive results (AOR: 0.67, 95% CI: 0.59-0.74) experienced a lower health system delay. Besides, the median of patient delay, health system delay, and total delay during the COVID-19 pandemic were significantly lower than that before.

Conclusion

In general, there has been a noteworthy decline in the notification rate of PTB among adolescents and young adults in Jiaxing City while the declining trend was not obvious in patient delay, health system delay, and total delay, respectively. It also found factors such as gender, case-finding method, and the hospital level might influence the times of seeking health care and diagnosis in health agencies. These findings will provide valuable insights for refining preventive and treatment strategies for TB among adolescents and young adults.

Epidemiological Characteristics and Their Influencing Factors Among Pulmonary Tuberculosis Patients With and Without Diabetes Mellitus: A Survey Study From Drug Resistance Surveillance in East China

Background

The burden of pulmonary tuberculosis (TB) and diabetes mellitus (DM) have become serious global concerns, while the comprehensive evaluations of DM status and drug resistance in TB patients are still lacking.

Methods

All details of TB cases were collected from drug resistance monitoring sentinels in Zhejiang province. Fisher's exact test or Pearson chi-square test (χ²) was used to compare the baseline characteristics among TB with different DM statuses. The logistic regression model was used to estimate the relationship between DM and different drug resistance spectra. Univariate analysis and multivariate logistic model were used to explore the possible risk factors of drug resistance in TB patients with DM and no DM.

Results

936 TB cases with smear-positive in Zhejiang province were collected, in which 76 patients (8.12%) owned the co-morbidity of DM. TB-DM prevalence was higher in older, Han nationality, employed, accompanied by no health insurance and hepatitis B status. Among 860 cases of TB-no DM and 76 cases of TB-DM, drug resistance-TB accounted for 31.51% and 23.68% (P > 0.05), MR-TB accounted for 15.93% and 14.47% (P > 0.05), respectively. MDR-TB was 4.88% and 6.58% (P > 0.05). The incidence of poly-drug resistant tuberculosis (PDR-TB) in TB-no DM patients (10.70 vs. 2.63%, OR: 4.43; 95% CI, 1.07–18.36) was higher than that in the TB-DM group (P < 0.05). In univariate and multivariate analysis, none of the basic factors were statistically significant with drug resistance among TB-DM cases (all P > 0.05). Retreatment was the risk factor of drug resistance among TB-no DM cases.

Conclusions

Our results showed that the drug resistance rate of the TB-DM group was not higher than that of the TB-no DM group. Patients with TB-no DM were at a higher risk for PDR-TB, but not for MDR-TB, MR-TB, and drug resistance-TB. Special attention should be paid to TB-no DM patients who have been previously treated. In the future, large-scale and well-designed prospective studies are needed to clarify the impact of DM on the drug-resistance among TB.

In vitro Synergism of Six Antituberculosis Agents Against Drug-Resistant Mycobacterium tuberculosis Isolated from Retreatment Tuberculosis Patients

Background

Retreatment tuberculosis (TB) has become a major source of drug-resistant TB. In contrast to the combination of isoniazid (INH) and rifampicin (RIF), that of pasiniazid (Pa) and rifabutin (RFB) or rifapentine (RFP) appears to have better activity in vitro against drug-resistant Mycobacterium tuberculosis (MTB), especially when combined with moxifloxacin (MXF). However, there has been limited study of potential synergism among Pa, RFB, RFP, and MXF, or simultaneous comparison with the standard INH and RIF combination.

Methods

In vitro synergism of four two-drug combinations (INH and RIF, Pa and RFB, Pa and RFP, MXF and Pa) and two three-drug combinations (MXF and Pa combined with RFB or RFP) was evaluated against 90 drug-resistant MTB strains isolated from retreatment TB patients by the checkerboard method. The fractional inhibitory concentration index (FICI) was calculated for each combination.

Results

The synergistic activity of the combination of Pa with RFB or RFP was higher than that of INH and RIF or MXF and Pa, and the synergistic activity of Pa in combination with RFP was even higher than that of RFB, although RFP yielded an MIC₉₀ of 64 mg/liter, higher than that of RFB of 8 mg/liter against 90 drug-resistant MTB strains. Meanwhile, for three-drug combinations, the synergistic effects of MXF and Pa combined with RFB or RFP were similar. Further stratification analysis showed that, for XDR-MTB strains, the synergistic effect of the Pa and RFP combination was also better than those of other two-drug combinations.

Conclusion

The combination of Pa with RFP shows better in vitro synergism than Pa with RFB and standard INH with RIF combinations, which can provide a reference for new regimens for retreatment TB patients.

Incidence and factors associated with unfavourable treatment outcome among patients with rifampicin-resistant pulmonary tuberculosis in Yaoundé, Cameroon

Introduction

in Cameroon patients with multidrug/rifampicin resistant pulmonary tuberculosis (MDR/RR-PTB) are treated with a 9-11 month standardised shorter treatment regimen. Despite its effectiveness, factors associated with the occurrence of an unfavourable treatment outcome in this group of patients are not known. Determine the incidence and identify factors associated with an unfavourable treatment outcome among patients with rifampicin resistant pulmonary tuberculosis (RR-PTB) in Yaoundé.

Methods

we conducted a retrospective record review of all consecutive patients with bacteriologically confirmed RR-PTB followed up at the specialised MDR/RR-TB treatment centre of the Jamot Hospital in Yaoundé (JHY) from January 2013 to November 2019. A patient was classified as having an unfavourable outcome if he/she had treatment failure, died or was lost to follow-up during the course of treatment.

Results

a total of 242 RR-PTB patients with a mean age of 35.59 ± 12.02 years including 144 (59.5%) males were registered. Forty-nine (49) of the 242 patients had an unfavourable treatment outcome giving a cumulative incidence of 20.20% (95% confidence interval (95% CI): 15.40-25.90%). Multivariable analysis revealed that patients with an unfavourable outcome were more likely to be males (odds ratio (OR): 2.94; 95% CI: 1.24-7.00, p= 0.015), HIV infected (OR: 2.67; 95% CI: 1.17-6.06, p = 0.019), and have a baseline haemoglobin level ≤ 10g/dl (OR: 2.87; 95% CI: 1.25-6.58, p = 0.013).

Conclusion

the rate of an unfavourable treatment outcome among patients with RR-PTB at the specialised MDR/RR-TB treatment centre of the JHY is relatively high. The male sex, HIV infection and moderate to severe anaemia are independent factors associated with an unfavourable treatment outcome.

Treatment outcomes and factors associated with unfavourable outcome among previously treated tuberculosis patients with isoniazid resistance in four regions of Cameroon

Introduction

it is unclear what the optimal treatment regimen for previously treated patients with rifampicin-susceptible isoniazid resistant tuberculosis should be. Conflicting evidence exists as to the effectiveness of the WHO standardized category II regimen in these patients. The objectives were to compare treatment outcomes between previously treated rifampicin-susceptible pulmonary tuberculosis patients with and without isoniazid resistance using the category II regimen and determine factors associated with an unfavourable outcome in those with isoniazid resistance in four regions of Cameroon.

Methods

we conducted a retrospective review of all bacteriologically confirmed previously treated rifampicin-susceptible patients with and without isoniazid resistance registered in four regions of Cameroon from January 2012 to March 2015.

Results

a total of 753 patients with a mean age of 38 ± 12 years including 498(66%) males were registered. Forty seven of the 753 had isoniazid-resistant TB, giving a prevalence of 6.2% (95% CI: 4.7-8.2). Treatment outcomes could only be ascertained for 733 patients as 20 (2.7%) were transferred out to other regions. Twenty-nine percent of patients with isoniazid resistance as against 21% of isoniazid susceptible patients had an unfavourable outcome (p = 0.32). In a multivariate logistic regression analysis, only HIV infection was significantly associated with an unfavourable outcome in isoniazid-resistant patients (p = 0.02).

Conclusion

treatment outcomes using WHO category II regimen in previously treated rifampicin -susceptible pulmonary tuberculosis patients with and without isoniazid resistance in four regions of Cameroon are similar. HIV infection is an independent risk factor for an unfavourable outcome in patients with rifampicin-susceptible isoniazid-resistant disease treated with this regimen.

Improvement cues of lesion absorption using the adjuvant therapy of traditional Chinese medicine Qinbudan tablet for retreatment pulmonary tuberculosis with standard anti-tuberculosis regimen

BACKGROUND

China is the second highest pulmonary tuberculosis (PTB) burden country worldwide. However, retreatment of PTB has often developed resistance to at least one of the four first-line anti-TB drugs. The cure rate (approximately 50.0-73.3%) and management of retreatment of PTB in China needs to be improved. Qinbudan decoction has been widely used to treat PTB in China since the 1960s. Previously clinical studies have shown that the Qinbudan tablet (QBDT) promoted sputum-culture negative conversion and lesion absorption. However, powerful evidence from a randomized controlled clinical trial is lacking. Therefore, the aim of this study was to compare the efficacy and safety of QBDT as an adjunct therapy for retreatment of PTB.

METHODS

We conducted a multicenter, randomized, double-blind, placebo-controlled clinical trial in China. People diagnosed with PTB were enrolled who received previous anti-TB treatment from April 2011 to March 2013. The treatment group received an anti-TB regimen and QBDT, and the control group was administered an anti-TB regimen plus placebo. Anti-TB treatment options included isoniazid, rifampicin, pyrazinamide, ethambutol, streptomycin for 2 months (2HRZES), followed by isoniazid, rifampicin, ethambutol for 6 months (6HRE), daily for 8 months. Primary outcome was sputum-culture conversion using the MGIT 960 liquid medium method. Secondary outcomes included lung lesion absorption and cavity closure. Adverse events and reactions were observed after treatment. A structured questionnaire was used to record demographic information and clinical symptoms of all subjects. Data analysis was performed by SPSS 25.0 software in the full analysis set (FAS) population.

RESULTS

One hundred eighty-one cases of retreatment PTB were randomly divided into two groups: the placebo group (88 cases) and the QBDT group (93 cases). A total of 166 patients completed the trial and 15 patients lost to follow-up. The culture conversion rate of the QBDT group and placebo group did not show a noticeable improvement by using the covariate sites to correct the rate differences (79.6% vs 69.3%; rate difference = 0.10, 95% confidence interval (CI): - 0.02-0.23; F = 2.48, P = 0.12) after treatment. A significant 16.6% increase in lesion absorption was observed in the QBDT group when compared with the placebo group (67.7% vs 51.1%; rate difference = 0.17, 95% CI: 0.02-0.31; χ² = 5.56, P = 0.02). The intervention and placebo group did not differ in terms of cavity closure (25.5% vs 21.1%; rate difference = 0.04, 95% CI: - 0.21-0.12; χ² = 0.27, P = 0.60). Two patients who received chemotherapy and combined QBDT reported pruritus/nausea and vomiting.

CONCLUSIONS

No significant improvement in culture conversion was observed for retreatment PTB with traditional Chinese medicine plus standard anti-TB regimen. However, QBDT as an adjunct therapy significantly promoted lesion absorption, thereby reducing lung injury due to Mycobacterium tuberculosis infection.

TRIAL REGISTRATION

This trial is registered at ClinicalTrials.gov, NCT02313610.

Prediction of the hidden genotype of mixed infection strains in Iranian tuberculosis patients

BACKGROUND

Patients with mixed-strain Mycobacterium tuberculosis infections may be at a high risk of poor treatment outcomes. However, the mechanisms through which mixed infections affect the clinical manifestations are not well recognized. Evidence suggests that failure to detect the pathogen diversity within the host can influence the clinical results. We aimed to investigate the effects of different genotypes in mixed infections and determine their relationship with heteroresistance in the treatment of Iranian tuberculosis patients.

METHODS

One of the genotypes was identified in the culture and another genotype pattern in the mixed infection was predicted by comparing the pattern of MIRU-VNTR between the clinical specimens and their respective cultures in each patient. For all patients, the drug susceptibility testing was carried out on three single colonies from each clinical sample. The follow-up of patients was carried out during six months of treatment.

RESULTS

Based on MIRU-VNTR profiles of clinical samples, we showed that 55.6% (25/45) of the Iranian patients included in the study had mixed infections. Patients with mixed infections had a higher rate of treatment failure, compared to others (P=0.03). By comparing clinical sample profiles to profiles obtained after culture, we were able to distinguish between major and hidden genotypes. Among hidden genotypes, Haarlem (L4.1.2) and Beijing (L2) were associated to treatment failure (6/8 patients).

CONCLUSIONS

To conclude, we propose a procedure using the MIRU-VNTR method to identify the different genotypes in mixed infections. The present findings suggest that genotypes with potentially higher pathogenicity may not be detected when performing experimental culture in patients with mixed infections.

ERS/ECDC Statement: European Union standards for tuberculosis care, 2017 update

The International Standards for Tuberculosis Care define the essential level of care for managing patients who have or are presumed to have tuberculosis, or are at increased risk of developing the disease. The resources and capacity in the European Union (EU) and the European Economic Area permit higher standards of care to secure quality and timely TB diagnosis, prevention and treatment. On this basis, the European Union Standards for Tuberculosis Care (ESTC) were published in 2012 as standards specifically tailored to the EU setting. Since the publication of the ESTC, new scientific evidence has become available and, therefore, the standards were reviewed and updated.A panel of international experts, led by a writing group from the European Respiratory Society (ERS) and the European Centre for Disease Prevention and Control (ECDC), updated the ESTC on the basis of new published evidence. The underlying principles of these patient-centred standards remain unchanged. The second edition of the ESTC includes 21 standards in the areas of diagnosis, treatment, HIV and comorbidities, and public health and prevention.The ESTC target clinicians and public health workers, provide an easy-to-use resource and act as a guide through all the required activities to ensure optimal diagnosis, treatment and prevention of TB.

Multidrug-resistant tuberculosis/rifampicin-resistant tuberculosis: Principles of management

Multidrug-resistant tuberculosis (MDR-TB)/rifampicin-resistant TB (RR-TB) is human-made problem and emerging due to poor management of TB and is a threat to control of TB. Early suspicion and diagnosis are important. Culture and drug susceptibility testing are gold standards, but newer molecular methods help in rapid diagnosis. Once diagnosed, prompt treatment should be started, preferably under direct observation. Treatment can be standardized or individualized. Conventional regimen takes up to 24 months but recently shorter regimen of up to 12 months was introduced in specific subset of MDR-TB/RR-TB patients. Management of MDR-TB/RR-TB is complicated, costlier, and challenging and is a concern for human health worldwide. It must be emphasized that optimal treatment of MDR-TB/RR-TB alone is not sufficient. Efforts must be made to ensure effective use of first- and second-line anti-TB drugs.

Current and developing therapies for the treatment of multi drug resistant tuberculosis (MDR-TB) in India

INTRODUCTION

India accounts for 25% of the global burden of MDR-TB. In 2016, the India's Revised National TB Control Programme reported a success rate of 46% among 19,298 MDR-TB patients treated under the programme. This suboptimal treatment outcome warrants an urgent need for newer drugs and newer regimens in the treatment of MDR-TB. India requires new shorter, cheap, safe and effective anti-TB regimen to treat MDR-TB. Areas covered: We used different search strategies to obtain relevant literature from PubMed, on Indian experiences of developing therapies for the treatment of MDR-TB. Further information from the Central TB Division Government of India on programmatic management of resistant TB was collected. Expert opinion: In 2016 WHO recommended a shorter MDR-TB regimen of 9-12 months (4-6 Km-Mfx-Pto-Cfz-Z-Hhigh-dose-E /5 Mfx-Cfz-Z-E) may be used instead of longer regimens. Currently, conducting trials involving newer drugs such as bedaquiline, have been proposed. The regimen will be of a shorter duration containing isoniazid, prothionamide, bedaquiline, levofloxacin, ciprofloxacin, ethambutol and pyrazinamide (STREAM regimen). To successfully treat MDR-TB one requires new classes of antibiotic and newer diagnostic tests. This represents an enormous financial and technical challenge to the programme managers and policy makers.

Evaluation of in vivo antimycobacterial activity of some folklore medicinal plants and enumeration of colony forming unit in murine model

Objectives:

The present study was carried out to investigate the in vivo antimycobacterial activity of methanol extract of Alstonia scholaris and Mucuna imbricata in murine model.

Materials and Methods:

Female BALB/c mice were infected with the Mycobacterium tuberculosis H₃₇Rv suspension. Extracts were administered orally for 2 weeks from 7^th day postinfection at a dose of 200 mg/kg and rifampicin at 20 mg/kg as standard. The synergistic groups were 10 and 100 mg/kg for rifampicin and extract, respectively.

Results:

The final body weight of mycobacteria-infected group was significantly reduced (15.41 ± 0.42, P < 0.01), but following treatment with the plant extract plus rifampicin could elevate the body weight. Colony forming unit (CFU) count of lung (8.71 ± 0.01) and spleen (8.59 ± 0.01) was significantly higher in infected and untreated group (P < 0.01). It was observed that activity of the synergistic group displayed powerful and maximum response against tuberculosis (TB) infection with lower CFU counts. Histopathology study showed cells such as lymphocytes, epithelioid, Langhans giant cell, and fibrous tissue proliferation in lungs; depletion of lymphocytes in the spleen.

Conclusions:

The data indicate that methanol extract of A. scholaris has potential antimycobacterial activity, and the synergistic group consisting of rifampicin and A. scholaris could be a rational choice for the treatment of TB.

Possible impact of the standardized Category IV regimen on multidrug-resistant tuberculosis patients in Mumbai

BACKGROUND

Treatment of multidrug-resistant tuberculosis (MDR-TB) in the Programmatic Management of Drug-resistant TB program involves a standard regimen with a 6-month intensive phase and an 18-month continuation phase. However, the local drug resistance patterns in high MDR regions such as Mumbai may not be adequately reflected in the design of the regimen for that particular area.

SETTING

The study was carried out at a private Tertiary Level Hospital in Mumbai in a mycobacteriology laboratory equipped to perform the second-line drug susceptibility testing (DST).

OBJECTIVE

We attempted to analyze the impact of prescribing the standardized Category IV regimen to all patients receiving a DST at our mycobacteriology laboratory.

MATERIALS AND METHODS

All samples confirmed to be MDR-TB and tested for the second-line drugs at Hinduja Hospital's Mycobacteriology Laboratory in the year 2012 were analyzed.

RESULTS

A total of 1539 samples were analyzed. Of these, 464 (30.14%) were MDR-TB, 867 (56.33%) were MDR with fluoroquinolone resistance, and 198 (12.8%) were extensively drug-resistant TB. The average number of susceptible drugs per sample was 3.07 ± 1.29 (assuming 100% cycloserine susceptibility). Taking 4 effective drugs to be the cut or an effective regimen, the number of patients receiving 4 or more effective drugs from the standardized directly observed treatment, short-course plus regimen would be 516 (33.5%) while 66.5% of cases would receive 3 or less effective drugs.

CONCLUSION

Our study shows that a high proportion of patients will have resistance to a number of the first- and second-line drugs. Local epidemiology must be factored in to avoid amplification of resistance.

High mortality associated with retreatment of tuberculosis in a clinic in Kampala, Uganda: a retrospective study

The World Health Organization recommends for tuberculosis retreatment a regimen of isoniazid (H), rifampicin (R), ethambutol (E), pyrazinamide (Z), and streptomycin (S) for 2 months, followed by H, R, E, and Z for 1 month and H, R, and E for 5 months. Using data from the National Tuberculosis and Leprosy Program registry, this study determined the long-term outcome under programmatic conditions of patients who were prescribed the retreatment regimen in Kampala, Uganda, between 1997 and 2003. Patients were traced to determine their vital status; 62% (234/377) patients were found dead. Having ≤ 2 treatment courses and not completing retreatment were associated with mortality in adjusted analyses.

[Management of multidrug-resistant tuberculosis]

The emergence of drug-resistant TB in many countries has become a major public health problem and an obstacle to effective tuberculosis control. Multidrug-resistant tuberculosis (MDR-TB), which is most often the result of poor adherence, is a particularly dangerous form of tuberculosis because it is caused by bacilli resistant to at least isoniazid and rifampicin, the two most effective anti-tuberculosis drugs. Techniques for rapid diagnosis of resistance have greatly improved the care of patients by allowing early treatment which remains complex and costly establishment, and requires skills and resources. The treatment is not standardized but it includes in all cases attack phase with five drugs (there must be an injectable agent and a fluoroquinolone that form the basis of the regimen) for eight months and a maintenance phase (without injectable agent) with a total duration of 20 months on average. Surgery may be beneficial as long as the lesions are localized and the patient has a good cardiorespiratory function. Evolution of MDR-TB treated is less favorable than tuberculosis with germ sensitive. The cure rate varies from 60 to 75% for MDR-TB, and drops to 30 to 40% for XDR-TB. Mortality remains high, ranging from 20 to 40% even up to 70-90% in people co-infected with HIV.

Mixed Mycobacterium tuberculosis complex infections and false-negative results for rifampin resistance by GeneXpert MTB/RIF are associated with poor clinical outcomes

The Xpert MTB/RIF (Xpert) assay is becoming a principal screening tool for diagnosing rifampin-resistant Mycobacterium tuberculosis complex (MTBC) infection. However, little is known about the performance of the Xpert assay in infections with both drug-sensitive and drug-resistant strains (mixed MTBC infections). We assessed the performance of the Xpert assay for detecting rifampin resistance using phenotypic drug sensitivity testing (DST) as the reference standard in 370 patients with microbiologically proven pulmonary tuberculosis. Mixed MTBC infections were identified genetically through 24-locus mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) analysis. Logistic regression was used to identify the factors associated with poor (defined as treatment failure, default, and death from any cause) or good (defined as cure or successful treatment completion) clinical outcomes. The analytic sensitivity of the Xpert assay for detecting rifampin resistance was assessed in vitro by testing cultures containing different ratios of drug-sensitive and drug-resistant organisms. Rifampin resistance was detected by the Xpert assay in 52 (14.1%) and by phenotypic DST in 55 (14.9%) patients. Mixed MTBC infections were identified in 37 (10.0%) patients. The Xpert assay was 92.7% (95% confidence interval [CI], 82.4% to 97.9%) sensitive for detecting rifampin resistance and 99.7% (95% CI, 98.3% to 99.9%) specific. When restricted to patients with mixed MTBC infections, Xpert sensitivity was 80.0% (95% CI, 56.3 to 94.3%). False-negative Xpert results (adjusted odds ratio [aOR], 6.6; 95% CI,1.2 to 48.2) and mixed MTBC infections (aOR, 6.5; 95% CI, 2.1 to 20.5) were strongly associated with poor clinical outcome. The Xpert assay failed to detect rifampin resistance in vitro when <90% of the organisms in the sample were rifampin resistant. Our study indicates that the Xpert assay has an increased false-negative rate for detecting rifampin resistance with mixed MTBC infections. In hyperendemic settings where mixed infections are common, the Xpert results might need further confirmation.

Management of patients with multidrug-resistant/extensively drug-resistant tuberculosis in Europe: a TBNET consensus statement

The emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) substantially challenges TB control, especially in the European Region of the World Health Organization, where the highest prevalence of MDR/XDR cases is reported. The current management of patients with MDR/XDR-TB is extremely complex for medical, social and public health systems. The treatment with currently available anti-TB therapies to achieve relapse-free cure is long and undermined by a high frequency of adverse drug events, suboptimal treatment adherence, high costs and low treatment success rates. Availability of optimal management for patients with MDR/XDR-TB is limited even in the European Region. In the absence of a preventive vaccine, more effective diagnostic tools and novel therapeutic interventions the control of MDR/XDR-TB will be extremely difficult. Despite recent scientific advances in MDR/XDR-TB care, decisions for the management of patients with MDR/XDR-TB and their contacts often rely on expert opinions, rather than on clinical evidence.

This document summarises the current knowledge on the prevention, diagnosis and treatment of adults and children with MDR/XDR-TB and their contacts, and provides expert consensus recommendations on questions where scientific evidence is still lacking.

TBNET consensus statement on the management of patients with MDR/XDR-TB has been released in theEur Respir Jhttp://ow.ly/uizRD

Common errors in multidrug-resistant tuberculosis management

Multidrug-resistant tuberculosis (MDR-TB), defined as being resistant to at least rifampicin and isoniazid, has an increasing burden and threatens TB control. Diagnosis is limited and usually delayed while treatment is long lasting, toxic and poorly effective. MDR-TB management in scarce-resource settings is demanding however it is feasible and extremely necessary. In these settings, cure rates do not usually exceed 60-70% and MDR-TB management is novel for many TB programs. In this challenging scenario, both clinical and programmatic errors are likely to occur. The majority of these errors may be prevented or alleviated with appropriate and timely training in addition to uninterrupted procurement of high-quality drugs, updated national guidelines and laws and an overall improvement in management capacities. While new tools for diagnosis and shorter and less toxic treatment are not available in developing countries, MDR-TB management will remain complex in scarce resource settings. Focusing special attention on the common errors in diagnosis, regimen design and especially treatment delivery may benefit patients and programs with current outdated tools. The present article is a compilation of typical errors repeatedly observed by the authors in a wide range of countries during technical assistant missions and trainings.

European union standards for tuberculosis care

The European Centre for Disease Prevention and Control (ECDC) and the European Respiratory Society (ERS) jointly developed European Union Standards for Tuberculosis Care (ESTC) aimed at providing European Union (EU)-tailored standards for the diagnosis, treatment and prevention of tuberculosis (TB). The International Standards for TB Care (ISTC) were developed in the global context and are not always adapted to the EU setting and practices. The majority of EU countries have the resources and capacity to implement higher standards to further secure quality TB diagnosis, treatment and prevention. On this basis, the ESTC were developed as standards specifically tailored to the EU setting. A panel of 30 international experts, led by a writing group and the ERS and ECDC, identified and developed the 21 ESTC in the areas of diagnosis, treatment, HIV and comorbid conditions, and public health and prevention. The ISTCs formed the basis for the 21 standards, upon which additional EU adaptations and supplements were developed. These patient-centred standards are targeted to clinicians and public health workers, providing an easy-to-use resource, guiding through all required activities to ensure optimal diagnosis, treatment and prevention of TB. These will support EU health programmes to identify and develop optimal procedures for TB care, control and elimination.

Multidrug and extensively drug-resistant tuberculosis management: Evidences and controversies

Multi-drug and extensively drug resistant tuberculosis (M/XDR-TB) has been an area of growing concern among clinicians, epidemiologists, and public health workers worldwide. Lack of controlled trials in M/XDR-TB patients hinders the optimal management of such patients, and guidelines that have been developed based largely on expert opinion are controversial. Lack of new effective drugs, improper regimens prescribed by poorly trained doctors and unreliable drug susceptibility testing add to the magnitude of the problem. M/XDR-TB is mostly a man made problem and its emergence can be checked by prompt diagnosis and effective use of first-line drugs in every new patient. DOTS-Plus proposed by World Health Organization (WHO) has highlighted the comprehensive management strategy to control multi-drug resistant tuberculosis (MDR-TB). Laboratory services must be strengthened for adequate and timely diagnosis of M/extensively drug resistant tuberculosis (XDR-TB) and programmatic management of M/XDR-TB must be scaled up as per target set by global plan to stop TB 2011-2015. In MDR-TB patients with localized disease, surgery, as an adjunct to chemotherapy, can improve outcomes and should be considered when there is poor response to appropriate chemotherapy. Proper use of second-line drugs must be ensured to cure existing MDR-TB, to reduce its transmission and to prevent emergence of XDR-TB.

Antitubercular effect of 8-[(4-Chloro phenyl) sulfonyl]-7-Hydroxy-4-Methyl-2H-chromen-2-One in guinea pigs

OBJECTIVE

TO EVALUATE THE ANTITUBERCULAR EFFICACY AND SAFETY OF NEW CHEMICAL ENTITY (NCE): 8-[(4-Chloro phenyl) sulfonyl]-7-Hydroxy-4-Methyl-2H-chromen-2-One (CSHMC) in guinea pigs.

MATERIALS AND METHODS

This pilot study was carried out in guinea pigs. They were infected with M. tuberculosis H(37)Rv (1.5 × 10(4) cfu/guinea pig) via intramuscular route. After 30 days, infections were confirmed in 6 guinea pigs by histopathology of spleen, lung, and liver. After that CSHMC (5 and 20 mg/kg) was administered for 1 month and its effect was compared with vehicle, rifampicin (60 mg/kg) and isoniazid (30 mg/kg). Efficacy of CSHMC was evaluated on the basis of histopathologic scoring of lesion in lung, spleen, liver, and safety on the basis of measuring hemogram, liver and renal function parameters.

RESULTS

Isoniazid, rifampicin, and CSHMC (20 mg/kg) significantly reduce the median lesion score in lung, spleen, and liver as compared to disease control group. Reduction in median lesion score for lung and spleen were not statistically significant for CSHMC 5 mg/kg. CSHMC (20 and 5 mg/kg) did not produce any changes in hemogram, liver and renal function parameters with respect to normal values.

CONCLUSIONS

CSHMC had shown significant antitubercular efficacy comparable to isoniazid and rifampicin and did not show hematological, hepato- and nephrotoxicity.

Increasing drug resistance of Mycobacterium tuberculosis in Sinaloa, Mexico, 1997-2005

BACKGROUND

In 1997 the US Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) reported high proportions of drug-resistant Mycobacterium tuberculosis in three Mexican states: Sinaloa, Baja California, and Oaxaca. In 2006, we showed that resistance to anti-tuberculosis drugs remained frequent in Sinaloa.

OBJECTIVES

The objectives of this study were to describe drug-resistant tuberculosis (TB) trends and to investigate the probability that patients acquire resistance to first-line anti-TB drugs on recurrence after treatment in Sinaloa.

METHODS

Sputum specimens were collected from patients diagnosed with TB at all the health care institutions of Sinaloa during 1997-2005. Isolates were tested for susceptibility to first-line drugs.

RESULTS

Among 671 isolates tested from 1997 to 2002, the overall resistance rate was 34.9% (95% confidence interval (CI) 31.2-38.4) with a 1.2% increase per year (Chi-square=4.258, p=0.03906). The prevalence of multi-drug resistance (MDR) was 17.9% (95% CI 14.9-20.7) with a 1.2% increase per year (Chi-square=8.352, p=0.00385). Of 50 patients registered twice between 1997 and 2005, 15 were fully susceptible at first registration, of whom six (40%) acquired drug resistance. Of 35 cases with any drug resistance at first registration, 21 (60%) came to acquire resistance to at least one other drug.

CONCLUSIONS

The proportion of drug-resistant TB increased during 1997-2005 in Sinaloa. Major efforts are needed to prevent the further rise and spread of drug-resistant and MDR TB.

Factors associated with multidrug-resistant tuberculosis: comparison of patients born inside and outside of the Czech Republic

Multidrug-resistant tuberculosis (MDR-TB) is defined as resistance of Mycobacterium tuberculosis complex (MTB) to at least isoniazid and rifampicin. The aim of this study was to evaluate and compare a cohort of 50 patients with MDR-TB according to birthplace, resistance type, clinical outcome, length of bacteriological positivity of sputum and length of hospitalization. Thirty-three of the patients were born in the Czech Republic (group A) and 17 were immigrants to the Czech Republic (group B). Patients in group B were significantly younger (mean [range] age 33 [19 - 56] years) than those in group A (mean [range] age 48 [33 - 80] years). Primary resistance was present in 16 (48%) cases in group A and in 13 (76%) cases in group B. There were 36 (72%) cured patients, five (10%) remained on treatment and nine (18%) died; no patients failed or transferred out of the study. The mean length of bacteriological positivity of sputum samples was 5.9 months and the mean length of hospitalization was 8.2 months. Resistance to capreomycin was an important predictor of poor outcome.

Best drug treatment for multidrug-resistant and extensively drug-resistant tuberculosis

Multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis are generally thought to have high mortality rates. However, many cases can be treated with the right combination and rational use of available antituberculosis drugs. This Review describes the evidence available for each drug and discusses the basis for recommendations for the treatment of patients with MDR and XDR tuberculosis. The recommended regimen is the combination of at least four drugs to which the Mycobacterium tuberculosis isolate is likely to be susceptible. Drugs are chosen with a stepwise selection process through five groups on the basis of efficacy, safety, and cost. Among the first group (the oral first-line drugs) high-dose isoniazid, pyrazinamide, and ethambutol are thought of as an adjunct for the treatment of MDR and XDR tuberculosis. The second group is the fluoroquinolones, of which the first choice is high-dose levofloxacin. The third group are the injectable drugs, which should be used in the following order: capreomycin, kanamycin, then amikacin. The fourth group are called the second-line drugs and should be used in the following order: thioamides, cycloserine, then aminosalicylic acid. The fifth group includes drugs that are not very effective or for which there are sparse clinical data. Drugs in group five should be used in the following order: clofazimine, amoxicillin with clavulanate, linezolid, carbapenems, thioacetazone, then clarithromycin.

Tuberculosis, drug resistance, and HIV/AIDS: a triple threat

The worldwide epidemics of tuberculosis (TB) and HIV/AIDS have been joined by an insidiously developing third epidemic of TB drug resistance. Fueled by the disruption of TB control programs and the explosive growth of HIV/AIDS, the presence of TB drug resistance, particularly multiple drug resistance, is worldwide and threatens the gains made in the past decades in the treatment of both TB and HIV. Although treatment success is possible, the diagnosis and treatment of drug-resistant TB is difficult. Advances in TB diagnosis and treatment have been minimal in the past 40 years, and there is an urgent need for wider distribution of available diagnostic technology and for the development and testing of newer rapid molecular diagnostic techniques and therapeutic agents. This review discusses current information about the distribution of multiple drug-resistant and newer extensively drug-resistant TB as well as available diagnostic and therapeutic strategies with an emphasis on the relationship between TB drug resistance and HIV/AIDS.

Management of multidrug-resistant tuberculosis: an update

Multidrug-resistant tuberculosis (MDR-TB) is threatening control of TB in many parts of the world. As a result of limited treatment options, patients have a poor prognosis and low chances of cure. This situation can be exacerbated by HIV epidemics. In some cases, the risk exists of a real shift from susceptible to resistant strains. Despite its relevance, currently there are more contradictions and confusion surrounding MDR-TB than hard evidence. No randomized controlled trials have been performed and published evidence is limited. Rather than just the selection of expensive drugs, MDR-TB management requires well-structured programmes with a comprehensive approach, which involve the actions of a wide range of participants. Even with current investments in research and development, new drugs and vaccines will take many years to be applied in low and middle income countries. The most successful results will depend on the optimization of existing tools. The majority of the patients, even those with extensive patterns of bacilli resistance, have a possibility of cure if current clinical knowledge and effective logistics are applied. This paper is a critical review of current best practice regarding the diagnosis and treatment of MDR-TB.

A short-term model for preliminary screening of potential anti-tubercular compounds

Screening of new agents for anti-tubercular activity is a challenging task due to the virulent and slow growing nature of mycobacteria. In this study, we explored the use of Mycobacterium smegmatis as an alternate model to virulent strains. We observed that the effect of standard anti-tubercular drugs was similar in mice infected with M. smegmatis and Mycobacterium tuberculosis. The total duration of the experiment, including incubation time, was 10 days in the M. smegmatis-infected mice model compared with 2 months in M. tuberculosis-infected mice. This model of anti-tubercular screening is a simple, easy to carry out, less time-consuming, safer and economical alternative for preliminary in vivo screening of potential anti-tubercular agents.

Tuberculosis in the 21st century: Challenges, endeavors and recommendations to doctors

The magnitude of problem with tuberculosis lies in the fact that one third of the world population is infected by Mycobacterium tuberculosis. Even in the 21st century, tuberculosis kills more people than any other infective agent. Definition of case of resistance - the case of resistant tuberculosis is precisely defined by the recommendations of the World Health Organization as primary, initial, acquired multidrug resistant and extensively drug resistant tuberculosis. The development of resistance tuberculosis may result from the administration of monotherapy or inadequate combinations of anti-tuberculosis drugs. A possible role of doctors in the development of multi drug-resistant tuberculosis is very important. Actually, multi drug-resistant tuberculosis is a direct consequence of mistakes in prescribing chemotherapy, provision of anti-tuberculosis drugs, surveillance of the patient and decision-making regarding further treatment as well as in a wrong way of administration of anti-tuberculosis drugs. The problem of extensively drug-resistant tuberculosis in the world has become very alarming. In South Africa, extensively drug resistant tuberculosis accounts for 24% of all tuberculosis case. It can be concluded that only adequate treatment according to directly supervised short regiment for correctly categorized cases of tuberculosis can stop the escalation of multidrug or extensively drug resistant tuberculosis, which is actually an incurable illness in the 21st century.

A simple scoring system to differentiate between relapse and re-infection in patients with recurrent melioidosis

BACKGROUND

Melioidosis is an important cause of morbidity and mortality in East Asia. Recurrent melioidosis occurs in around 10% of patients following treatment either because of relapse with the same strain or re-infection with a new strain of Burkholderia pseudomallei. Distinguishing between the two is important but requires bacterial genotyping. The aim of this study was to develop a simple scoring system to distinguish re-infection from relapse.

METHODS

In a prospective study of 2,804 consecutive adult patients with melioidosis presenting to Sappasithiprasong Hospital, NE Thailand, between 1986 and 2005, there were 141 patients with recurrent melioidosis with paired strains available for genotyping. Of these, 92 patients had relapse and 49 patients had re-infection. Variables associated with relapse or re-infection were identified by multivariable logistic regression and used to develop a predictive model. Performance of the scoring system was quantified with respect to discrimination (area under receiver operating characteristic curves, AUC) and categorization (graphically). Bootstrap resampling was used to internally validate the predictors and adjust for over-optimism.

FINDINGS

Duration of oral antimicrobial treatment, interval between the primary episode and recurrence, season, and renal function at recurrence were independent predictors of relapse or re-infection. A score of < 5 correctly identified relapse in 76 of 89 patients (85%), whereas a score > or = 5 correctly identified re-infection in 36 of 52 patients (69%). The scoring index had good discriminative power, with a bootstrap bias-corrected AUC of 0.80 (95%CI: 0.73-0.87).

CONCLUSIONS

A simple scoring index to predict the cause of recurrent melioidosis has been developed to provide important bedside information where rapid bacterial genotyping is unavailable.

Treatment outcomes for HIV-uninfected patients with multidrug-resistant and extensively drug-resistant tuberculosis

BACKGROUND

Multidrug-resistant (MDR) tuberculosis (TB) is more difficult to treat than is drug-susceptible TB. To elucidate the optimal therapy for MDR TB, we assessed the treatment outcomes and prognostic factors for patients with MDR TB.

METHODS

This study included patients who received an individualized treatment regimen for MDR TB at Samsung Medical Center, a tertiary referral hospital in Seoul, Korea, from January 1995 through December 2004. To identify the prognostic factors related to favorable treatment outcomes, univariate comparison and multiple logistic regression were performed.

RESULTS

Of 155 patients, 18 (12%) had newly diagnosed MDR TB, 81 (52%) had previously received treatment with first-line drugs, and 56 (36%) had received treatment with second-line drugs. The isolated strains were resistant to a median of 5 drugs. Twenty-seven patients (17%) had extensively drug-resistant (XDR) TB at the start of treatment. Outcome assessment revealed that 102 patients (66%) were cured or completed therapy. The treatment success rates did not differ significantly between patients with non-XDR MDR TB and those with XDR TB (66% vs. 67%). Surgical resection was performed more frequently for patients with XDR TB than for those with non-XDR MDR TB (48% vs. 17%). Combined surgical resection, body mass index >/=18.5 (calculated as the weight in kilograms divided by the square of the height in meters), use of >4 effective drugs, and a negative sputum smear result were independent predictors of a favorable outcome.

CONCLUSIONS

Early aggressive treatment comprising at least 4 effective drugs and surgical resection, when indicated, may improve the outcome for patients with MDR TB or XDR TB.

Management of extensively drug-resistant tuberculosis in Peru: cure is possible

Aim

To describe the incidence of extensive drug-resistant tuberculosis (XDR-TB) reported in the Peruvian National multidrug-resistant tuberculosis (MDR-TB) registry over a period of more than ten years and present the treatment outcomes for a cohort of these patients.

Methods

From the Peruvian MDR-TB registry we extracted all entries that were approved for second-line anti-TB treatment between January 1997 and June of 2007 and that had Drug Susceptibility Test (DST) results indicating resistance to both rifampicin and isoniazid (i.e. MDR-TB) in addition to results for at least one fluoroquinolone and one second-line injectable (amikacin, capreomycin and kanamycin).

Results

Of 1,989 confirmed MDR-TB cases with second-line DSTs, 119(6.0%) XDR-TB cases were detected between January 1997 and June of 2007. Lima and its metropolitan area account for 91% of cases, a distribution statistically similar to that of MDR-TB. A total of 43 XDR-TB cases were included in the cohort analysis, 37 of them received ITR. Of these, 17(46%) were cured, 8(22%) died and 11(30%) either failed or defaulted treatment. Of the 14 XDR-TB patients diagnosed as such before ITR treatment initiation, 10 (71%) were cured and the median conversion time was 2 months.

Conclusion

In the Peruvian context, with long experience in treating MDR-TB and low HIV burden, although the overall cure rate was poor, a large proportion of XDR-TB patients can be cured if DST to second-line drugs is performed early and treatment is delivered according to the WHO Guidelines.

Impact of extensive drug resistance on treatment outcomes in non-HIV-infected patients with multidrug-resistant tuberculosis

BACKGROUND

Recently, serious concerns about extensively drug-resistant tuberculosis (XDR-TB), which shows resistance to second-line anti-TB drugs in addition to isoniazid and rifampicin, have been raised. The aim of this study was to elucidate the impact of extensive drug resistance on treatment outcomes in non-human immunodeficiency virus (HIV)-infected patients with multidrug-resistant tuberculosis (MDR-TB).

METHODS

Patients who received the diagnosis of and treatment as having MDR-TB at Seoul National University Hospital (Seoul, Republic of Korea) between January 1996 and December 2005 were included. The definition of XDR-TB was TB caused by bacilli showing resistance to both isoniazid and rifampicin and also showing resistance to any fluoroquinolone and to at least 1 of the following 3 injectable anti-TB drugs: capreomycin, kanamycin, and amikacin. To identify the impact of extensive drug resistance on treatment outcomes, univariate comparison and multiple logistic regression were performed.

RESULTS

A total of 211 non-HIV-infected patients with MDR-TB were included in the final analysis. Among them, 43 patients (20.4%) had XDR-TB. Treatment failure was observed in 19 patients (44.2%) with XDR-TB, whereas treatment of 46 patients (27.4%) with non-XDR-TB failed (P=.057). The presence of extensive drug resistance (adjusted odds ratio [OR], 4.46; 95% confidence interval [CI], 1.35-14.74) and underlying comorbidity (adjusted OR, 2.62; 95% CI, 1.00-6.87) were independent risk factors for treatment failure. However, a higher level of albumin was inversely associated with treatment failure (adjusted OR, 0.87; 95% CI, 0.77-0.97).

CONCLUSION

The presence of extensive drug resistance, the presence of comorbidity, and hypoalbuminemia were independent poor prognostic factors in non-HIV-infected patients with MDR-TB.

Guía de práctica clínica de la Sociedad Andaluza de Enfermedades Infecciosas (SAEI) sobre el tratamiento de la tuberculosis

The therapeutic scheme for initial pulmonary tuberculosis recommended by the SAEI is as follows: Initial phase, isoniazid, rifampin and pyrazinamide given daily for 2 months. In HIV(+) patients and immigrants from areas with a rate of primary resistance to isoniazid > 4%, ethambutol should be added until susceptibility studies are available. Second phase (continuation phase): rifampin and isoniazid, given daily or intermittently for 4 months in the general population. HIV(+) patients (< or = 200 CD4) and culture-positive patients after 2 months of treatment should receive a 7-month continuation phase. A 6-month regimen is recommended for extrapulmonary tuberculosis, with the exception of tuberculous meningitis, which should be treated for a minimum of 12 months and bone/joint tuberculosis, treated for a minimum of 9 months. Treatment regimens for multidrug resistant tuberculosis are based on expert opinion. These would include a combination of still-useful first-line drugs, injectable agents, and alternative agents, such as quinolones. Patients who present a special risk of transmitting the disease or of non-adherence should be treated with directly observed therapy.

International standards for tuberculosis care

Part of the reason for failing to bring about a more rapid reduction in tuberculosis incidence worldwide is the lack of effective involvement of all practitioners-public and private-in the provision of high quality tuberculosis care. While health-care providers who are part of national tuberculosis programmes have been trained and are expected to have adopted proper diagnosis, treatment, and public-health practices, the same is not likely to be true for non-programme providers. Studies of the performance of the private sector conducted in several different parts of the world suggest that poor quality care is common. The basic principles of care for people with, or suspected of having, tuberculosis are the same worldwide: a diagnosis should be established promptly; standardised treatment regimens should be used with appropriate treatment support and supervision; response to treatment should be monitored; and essential public-health responsibilities must be carried out. Prompt and accurate diagnosis, and effective treatment are essential for good patient care and tuberculosis control. All providers who undertake evaluation and treatment of patients with tuberculosis must recognise that not only are they delivering care to an individual, but they are also assuming an important public-health function. The International Standards for Tuberculosis Care (ISTC) describe a widely endorsed level of care that all practitioners should seek to achieve in managing individuals who have, or are suspected of having, tuberculosis. The document is intended to engage all care providers in delivering high quality care for patients of all ages, including those with smear-positive, smear-negative, and extra-pulmonary tuberculosis, tuberculosis caused by drug-resistant Mycobacterium tuberculosis complex, and tuberculosis combined with HIV infection.